I don't quite get the "GDPR requires you to share with someone the personal details of people who happened to visit a webpage that you setup on a free website" angle here. I don't get how that's your data and not the data of the people who visited the page?

That seems to violate the GDPR more than the current state, no? If I accidentally click on your profile you're entitled to my name and employer and that's your data now? Makes no sense, other than from a "GDPR good, US tech bad!" angle, I guess.

Agree, I don't fully understand the argument that this would be the owning profiles data, and not either Linkedin's or the viewer's. Would you be entitled to search query data from Google because your website is in some query results, and Google has to provide you that metadata for free?

I believe that the case here is different. That would be true, say, for your substack page. But in this case, your "profile" is more than just a web page, it contains personal information, which albeit public, is your property according to the law. Therefore any interaction with it falls under article 15. Personally I would find it fantastic if LinkedIn is forced to make this feature available to all users. I can't see it but as a win for consumers and a loss for inducing payment through extraction of interrelational value.